Purpose: To describe clinical and histopathological findings of an uveal melanoma associated with nevus of Ota in a dog. Methods: A 4-year-old, male, German Shepherd dog, was presented with a three-day history of ocular pain in the right eye. Anamnesis reported facial skin pigmentation on the right side since puppyhood. Ophthalmological examination revealed diffuse corneal edema, vascular scleral congestion, diffuse iris iperpigmentation, iris bombè, and discoria; intraocular pressure was 41mmHg. Ipsilateral facial skin was diffusely hyperpigmented. Left eye did not show abnormalities. Right eye ultrasonography showed severe iris thickening. Due to clinical signs, enucleation was performed and the globe was submitted to histological examination. Preoperative thoracic radiography and abdominal ultrasonography were declined by owners. Results: Histologically, anterior uveal architecture was effaced by an infiltrating neoplasia, with transcleral extension to surrounding orbital tissues. Pleomorphic, polygonal to spindle, neoplastic cells were organized in nest or pseudorosettes. Intracytoplasmic melanin granules were occasionally visible. Mitoses ranged from 0 to 9/HPF (IM 4.4). Anterior uveal melanoma was diagnosed. The dog died because of pulmonary metastases two months after enucleation. Conclusion: Nevus of Ota is an oculodermal melanocytosis characterized by accumulation of melanocytes in the ocular and cutaneous tissues corresponding to the distribution of the ophthalmic and maxillary branches of the trigeminal nerve. Human patients showing oculodermal melanocytosis are at increased risk of developing uveal melanoma, as well as melanoma of the ipsilateral skin. To the authors’ knowledge, this is the first report of an uveal melanoma associated with nevus of Ota in a dog.
UVEAL MELANOMA ASSOCIATED WITH NEVUS OF OTA IN A GERMAN SHEPHERD
Barsotti G.;
2021-01-01
Abstract
Purpose: To describe clinical and histopathological findings of an uveal melanoma associated with nevus of Ota in a dog. Methods: A 4-year-old, male, German Shepherd dog, was presented with a three-day history of ocular pain in the right eye. Anamnesis reported facial skin pigmentation on the right side since puppyhood. Ophthalmological examination revealed diffuse corneal edema, vascular scleral congestion, diffuse iris iperpigmentation, iris bombè, and discoria; intraocular pressure was 41mmHg. Ipsilateral facial skin was diffusely hyperpigmented. Left eye did not show abnormalities. Right eye ultrasonography showed severe iris thickening. Due to clinical signs, enucleation was performed and the globe was submitted to histological examination. Preoperative thoracic radiography and abdominal ultrasonography were declined by owners. Results: Histologically, anterior uveal architecture was effaced by an infiltrating neoplasia, with transcleral extension to surrounding orbital tissues. Pleomorphic, polygonal to spindle, neoplastic cells were organized in nest or pseudorosettes. Intracytoplasmic melanin granules were occasionally visible. Mitoses ranged from 0 to 9/HPF (IM 4.4). Anterior uveal melanoma was diagnosed. The dog died because of pulmonary metastases two months after enucleation. Conclusion: Nevus of Ota is an oculodermal melanocytosis characterized by accumulation of melanocytes in the ocular and cutaneous tissues corresponding to the distribution of the ophthalmic and maxillary branches of the trigeminal nerve. Human patients showing oculodermal melanocytosis are at increased risk of developing uveal melanoma, as well as melanoma of the ipsilateral skin. To the authors’ knowledge, this is the first report of an uveal melanoma associated with nevus of Ota in a dog.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
